alternation

n.改变，变更

alphabetically, alphabetize, alpine, alpinist, already, alright, Alsatian, also, also-ran, altar, altar-piece, alter, alter ego, alterable, alteration, altercation, alternate, alternate angles, alternately, alternating current, alternative, alternatively, alternator, although, although (US also altho), altimeter, altitude, alto, altogether, altruism, altruist, altruistic, altruistically, alum, aluminium, aluminum, alumna, alumnus, alveolar, always,